Your kids are close together like mine. My daughter also did this at 2 when her brother was a few months old. She did this for several months. That was a difficult time. She usually did it when I was out of the house and my husband was watching the kids. The house that we lived in had mostly hardwood floors, unfortunately, the playroom had berber carpet. I came home once from my once in several months with visiting one of my girlfriends. There was a box fan blowing on the carpet in the toyroom. Only problem was daddy didn't do such a good cleanup job. I had to go in and take several toys that could go in the dishwasher to sterilize, threw several stuffed animals in the wash, threw out her pretty princess tent and cute froggy chair and went out that evening to rent a rinse n' vac. That was the worse time. She would get into her diapers or pull ups, didn't matter, she could get into them. I think it was an attention thing, curiosity, whatever, it was gross. I probably could have cleaned the tent and chair, but she had done it several times before and I said, if you are going to do this, your things will start to go bye bye. I tried keeping onsies, overalls and duct taping. Yes, DUCT TAPE. We would put a little piece of duct tape over the tabs of the diaper- making sure of course not to get the tape on her skin, just on the diaper - didn't want it to stick to her skin. My one suggestion, which may sound crazy is go out and buy a roll of duct tape, just be careful not to pull of a big piece- you just want a really small piece over the tabs - that way, they cant open the diaper. When its' time for a change, it's a little more difficult for you to open, but it's so worthwhile. My daughter started potty training soon after and was totally trained, day and night by 2 1/2. This shall pass. Just stock up on cleaning supplies and try to keep an eye on him as much as possible...I think this is why it happened when I wasn't around. Daddy has always been really good with the kids, but doesn't watch them every second like I do. Sure I don't get as much done around the house, but it's worth it to keep them safe!
I'm soooooooooooooooooooooo glad that my second child, my son has never done this. It's such a relief! So not all kids go through this stage, but many do. Hopefully your second child skips this!